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The presence of emerging contaminants, such as parabens, in aquatic environments and wastewater, have been causing great concern over the past years. Parabens (ethyl-paraben (EtP), methylparaben (MeP) and propylparaben (PrP)) are characteristic emerging contaminants and used as preservatives and have the potential to bioaccumulate. Due to their wide usage, parabens have been detected in various aquatic environments at concentrations ranging from 0.001 to 305.55 µg L-1. Conventional wastewater treatment methods are not capable of removing those types of contaminants. Over the last years, Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) have received considerable interest for the removal of organic micropollutants. As parabens are commonly found in mixtures in the aquatic environment, this study investigates the efficiency of two SR-AOPs (UV-C/Persulfate and UV-C/Peroxymonosulfate) to remove EtP, MeP and PrP as a mixture in ultrapure water and wastewater. Both SR-AOPs were proved to be efficient for the degradation of parabens and high removal percentages were observed in all cases. All compounds were removed at about 50% within 5 minutes using UV-C/Peroxymonosulfate process in ultrapure water. When wastewater was used as matrix, 50% removal was achieved in about 20 to 30 minutes. The above results suggest the dependence of the removal and the complexity of the water matrix. When UV-C/Persulfate was used to remove the parabens mixture the time needed to achieve 50% removal was higher than UVC/Peroxymonosulfate. [ABSTRACT FROM AUTHOR]

The catalytic oxidation of NO from waste gas was investigated using advanced oxidation process based on sulfate radicals. The manganese oxide immobilized on graphene oxide (GO) can activate peroxymonosulfate (PMS) for the oxidation of NO in water. The Mn3O4/GO catalysis system was characterized via X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that Mn3O4 was distributed on GO. The Mn3O4/GO catalyst system exhibited efficient activity for NO oxidation when the Mn3O4/GO catalyst has an optimum Mn3O4 loading. In addition, the best catalytic oxidation can be achieved within 30 min with pH 4 and 6 mM PMS at 25 ° C. Therefore, the results may have significant technical implication for utilizing Mn3O4/PMS to oxidize NO for offgas treatment. [ABSTRACT FROM AUTHOR]